Subject: [xsl] The evaluate function From: Mark Feblowitz <mfeblowitz@xxxxxxxxxxxxxxxx> Date: Wed, 2 Jan 2002 16:32:19 -0500 |
A few questions on xsl "evaluate" functions First, I noticed the following in the 20 December 2001 XSLT Version 2.0 working draft (http://www.w3.org/TR/2001/WD-xslt20-20011220/#dynamic-evaluation <http://www.w3.org/TR/2001/WD-xslt20-20011220/#dynamic-evaluation> ): Issue (evaluate-function): There is at present no consensus within the working group that such a function should be provided, as it has significant implications on the run-time architecture of the processor, as well as the ability to do static optimization. Are there leanings in either direction, or is this particular issue in deadlock? It seems that many questions on this list involve solutions that require use of an evaluate function. So the need is clearly there. Not having built an XSL processor, I'll take it on faith that such a capability could alter the architecture. It would seem that there would have to be two separate XPath evaluators if a processor were to support both the evaluation of static (optimized) XPath expressions and dynamic XPath expressions. What I don't understand is why there is an issue regarding static optimization. It would seem that those expressions that were to be dynamically evaluated could be flagged as such (e.g., using an explicit evaluate function) and not adversely affect optimized processing of static expressions. What am I missing? Other questions: Both Saxon and Xalan support evaluate functions. Are there widely used XSL processors that do not provide such a capability? Does MSXML provide an equivalent? How is it invoked? Do all of the existing implementations perform the evaluations uniformly? Could I expect Xalan and Saxon to evaluate the same XPath expression and get a different result (barring, of course, any bugs). Thanks, Mark ---------------------------------------------------------------------------- ---- Mark Feblowitz [t] 617.715.7231 Frictionless Commerce Incorporated [f] 617.495.0188 XML Architect [e] mfeblowitz@xxxxxxxxxxxxxxxx 400 Technology Square, 9th Floor Cambridge, MA 02139 www.frictionless.com XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
[xsl] XSL-List guidelines - Changed, Mulberry Technologie | Thread | RE: [xsl] The evaluate function, Evan Lenz |
Re: [xsl] Re: Assignment no, dynami, Gunther Schadow | Date | Re: [xsl] Re: Re: Assignment no, dy, Gunther Schadow |
Month |